The invention relates to an apparatus for imaging a layer to be examined of a body. The body is irradiated by primary radiation, and the layer emits scattered radiation. The apparatus comprises a diaphragm plate which is arranged outside the primary radiation, which is rotatable about an axis perpendicular to its major surface, and which has at least one aperture situated off of the axis of rotation. The apparatus further comprises a detector or a superposition device for measuring or superimposing the scattered radiation which passes through the diaphragm plate at different aperture settings.
Such an apparatus is known from DE-GM 75 41 605. By means of this apparatus, layer-images of the irradiated body can be examined in that initially the scattered radiation, which is emitted by the body and which propagates outside of the primary beam, is detected from different perspectives in order to record sub-images of the body. Subsequently, these sub-images are superimposed by means of a superposition device in such a way that the desired layer images of the body are obtained. The sub-images may, for example, be superimposed by means of the pinhole diaphragm used for recording the images.
As a result of the additional device for superimposing the sub-images, the apparatus has a comparatively intricate construction. Moreover, the contrast of the layer images thus generated is not satisfactory. This is because not only scattered radiation from the body layer to be displayed is measured, but scattered radiation from body areas adjacent to this body layer is also measured.